The spindles of a spinning or twisting frame are generally arranged in rows with respective whorls tangentially engaging a drive belt which rotates the spindle.
For each spindle, an individually actuatable brake is generally provided and brakes of a wide variety of constructions have been proposed and used for this purpose.
For example, in German patent document (Open Application) No. 29 22 606 a two-jaw brake is disclosed. The jaws are each carried on respective arms and the latter are urged against the spindle or a member connected thereto by tongs action.
Each of the arms is connected by a respective pin pivotally with a support at the upper end of the spindle housing.
While this arrangement is effective to bring the spindle to standstill, it has the disadvantage that the tangential belt continues to rub along the whorl which causes frictional distortion of the spindle and applies unnecessary stress to the bearing, at least in part as a result of the heat generated by the frictional action.
Another disadvantage of this system is that it requires a respective housing individual to each brake and thus complicates the mounting or dismounting of the brakes by requiring assembly or disassembly of the respective housings.
An earlier spindle brake is described in German Pat. No. 20 48 959 in which a single shoe brake cooperates, via a leaf spring device, with a roller adapted to lift the belt away from the immobilized spindle during the braking thereof.
The construction of this brake is complex and hence expensive and somewhat unreliable. Furthermore, this device has the disadvantage that one-sided force is applied to the whorl and the spindle during the braking action and can mechanically stress the bearings and reduce the operating life of the spindle or adversely affect its concentricity.